In smaller greenhouses, a manual system opened and closed yourself could be installed. These work simplest when the screen materials is backed by a track system.
Start time – when in the morning will the display screen system start operation
Stop period – when in the afternoon will the screen system stop operation
Light level – in what light strength will the screen be activated either to open up or close
Maximum/minimum temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What exactly are the limits of humidity desired
Gap positions – this pieces the percent open or close placement under different conditions such as early on a winter early morning to reduce thermal shock or through the 
summer to provide better shading. The gap methods and speed of motion can be controlled in a few systems.
Time delay – under changeable climate this avoids frequent opening and closing
Wind speed – To lessen high temperature loss, the screen could be closed early under high wind speed conditions
Snow detection – this can open the screen and turn on heat when it begins to snow.
The typical system uses nylon monofilament or stainless cables to Rack Drive For Greenhouse support the screen material. The screen material can either rest on top of the network of cables or become suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that movements the industry leading of the screen material. Control can be either with a manual change or electronic controller.
Based on the above, the grower must enter the next parameters in to the controller:
A weather station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.